Open-hearth furnace



A. T. KELLER OPEN HEARTH FURNAGE Julyv l, 1930.

Filed Dec. 5, 1921 2 Sheets-Sheet I l Elftor Icq July l, 1930.

OPEN HEARTH FURNACE Filed Dec. 5, 1921 2 Sheets-Sheet 2 @540% Mga/l A. 1*'. KELLER 1,769,842 y Patented July l, 193e UNITED STATES PATENT carica ALBERT T.- KELLER, OF BETHLEHEM, PENNSYLVANIA, ASSIGNOR, BY HESNE ASSIGN- MENTS, T OPEN HEABTH COHB'USTION COMPANY, A CORPORATION 0F NEW JERSEY OPEN -HEAETH FURNACE Application led December 5, 1921. Serial No. 520,042.

The present inventionlate's to regenerative furnaces and particularly to regenerative reverberatory furnaces of the type utilized in the meltitng of the charge in themanufacture of steel by the open-hearth process.

The object of the invention is to provide a lfurnace of this t pe havin novel means for controlling the incoming el and the port area for the out oing products of combustion 1o whereby the carge may be melted more quickly than' in the ordinary open-hearth furnace, thereb increasin the rate of production of the urnace an Without at the same time shortening its life. l

trated in the accompanying drawings in which: l

Figure 1 is a vertical lon 'tudinal central section through one end of t e furnace Figure 2 is a section on line 2--2 of-Figure 1 Figure 3 is asimilar section but showing certain parts in different positions; and

Figure 41is a 1an view of the end ofthe w furnace, partly roken away. Y

It will be understood that the ends of the furnace are preferably similarly constructed. The hearth is indicated at and is of usual construction, havin the upwardly inclined so end wall 10', and le roof 11 slopes downwardly towards the throat 12 through which the air and combustible gas to be burned pass to the combustion chamber at the inlet end of the furnace and the roducts of combustion pass at the outlet en of the furnace. This throat is long and relatively narrow in cross section, as can be seen in Fi res 2 and 3, and in the usual construction o the furnace will have a curved to and a straight horizontal bottom. It will e understood however that the precise cross sectional shape of the throat ma be varied as desired.

he roof of the furnace beyond the throat slopes upwardl and outwardly while the Hoor is substantially horizontal. Flues leading to air and gas regenerating chambers are in icated at 13 and 14 res ectively, and air uptakes 15 lead upwardly rom the flue 13 to ports 16 in the door of the furnace be ond the throat, and a gas uptake 17 leads rom the vserving as an inlet end, air and ne embodiment of the invention is illus-4 flue 14 upwardly horizontally toward the combustion chamber, terminating in a gas outlet port 18 positioned centrally of the furnace and arranged to discharge gases through lle throat 412 and into thecombustionchamer. A

When 'the end of the furnace illustrated is gas pass through the uptake iues 15 and 17 and thence through the throat 12 and into the combustion chamber, where they are burned. In order to regulate or throttle the iiow of air and at the same time to maintain its direction of flow from the ports 16 toward the center of the furnace,that is, toward the stream of gas isc5 suing from the port 18, suitable dampers or throttling devices now to be described are provide Formed .in the floor of the furnace at the throat' are grooves l19, which are curved as illustrated, and similar grooves are also formed in the roof directly above.- Each such pair of grooves constitutes a trackwalj7 for a cylindrical damper 20 which projects into the throat through a slot 21.. The dampers 20 are supported on arms 22 pivotally mounted at 23 on the outside of the furnace and are adapted to be swung about these pivotal axes into or out of the furnace to decrease or increase as desired the effective area of the throat,` thus enabling the air supply to \be throttled as desired, although it is never completely cut off. The gas port 18 is never obstructed by the dampers or throttling devices.

The dampers being curved, with their convex surfaces toward the air ports, serve as means for directing the incoming air on each side of the furnace toward the stream of incoming gas so that a combustible mixture is forme as the gas passes through the throat. The dampers 20 serve to direct the air in this manner even when moved outwardly to increase the effective area of the throat, for all positions of the dempers, except of course when they are completely withdrawn from the furnace.

When the end of the furnace illustrated is functioning as the outlet for the products of combustion, the dempers 20 may be complete- 100 l withdrawn, as shown in Figure 3, so that e throat is unobstructed and its entire crosssectional area is effective for carrying 'of the hot gases, which pass downwardly through the flues and 17 to the regenerat-v ing chambers. The area of the unobstructed throat is such that burning out of the walls of the gas port does not take place and the outgoin stream of products of combustion is not c ecked even when the incoming gas or air, or both, are under pressure.

The invention may be embodied in various types of furnaces and is not limited to any specific construction, within the scope of the ap nded claims.

i): will be understood that by the word hearth used in the appended claims to indicate the chamber into which the throat opens is meant combustion chamber. The combustion chamber is the chamber between the throats and enclosed by the hearth proper 10, 10', the roof 11, and the side walls.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. An end construction for regenerative open hearth furnaces having a throat for the passage of fuel to the hearth or for the esf cape of products of combustion, and means for varying the effective area of the throat including a damper pivotally supported on the outside of the furnace and adapted to be swung into and out of the throat through an openin in the side wall, said damper be- -ing curve about its pivotal axis as a center.

2. An end construction for regenerative open hearth furnaces having a throat for the passage of fuel to the hearth or for the escape of products of combustion, and means for var ing the effective area ofthe throat inclu ing two curved dampers movable into the throat from opposite sides thereof, the convex sides of said dampers facing away from the hearth.

3. An end construction for` regenerative open hearth furnaces having a throat for the passage of fuel to the hearth or for the escape of products of combustion, and means for var ing the effective area' of the throat inclu ing two dampers one on each side and being movable horizontally throu h the side wall of the furnace into the t roat, and grooves in the roof and floor of the furnace to receive the upper and lower edges of the dampers.

In testimony whereof I hereunto ailix my si gnature.

ALBERT T. KELLER. 

